Review of the current knowledge concerning youth violence and gang behavior considers risk factors for violence and gang formation, functions served by violence and gang membership, and strategies that have been empirically validated to be either beneficial or ineffective. Following an introductory chapter, the first chapter looks at the nature of aggression, including risk factors associated with aggression and violence, the function of violence, and peer association and the development of violence and aggression. The following chapter focuses on youth gangs including reasons for gang memberships and why schools cannot combat violence and gang activity alone. A self-study to help schools identify needs and resources is included. Next, prevention and intervention programs are addressed with emphasis on empirically validated or promising programs. The role of functional assessment of behavior and the student is then considered, followed by some cautionary notes concerning grouping high-risk students together for intervention, use of highly punitive consequences for behavior, and employing gang members or ex-gang members to deter gang affiliation. (Contains approximately 75 references.) (DB)